“And finally, what about the magical number seven? What about the seven wonders of the world, the seven seas, the seven deadly sins, the seven daughters of Atlas in the Pleiades, the seven ages of man, the seven levels of hell, the seven primary colors, the seven notes of the musical scale, and the seven days of the week? What about the seven-point rating scale, the seven categories for absolute judgment, the seven objects in the span of attention, and the seven digits in the span of immediate memory? For the present I propose to withhold judgment. Perhaps there is something deep and profound behind all these sevens, something just calling out for us to discover it. But I suspect that it is only a pernicious, Pythagorean coincidence.”
“In the psychology of information processing the number 7 is a somewhat “magical” invariant:
According to Miller (1956) it manifests itself as a constraint of the span of absolute judgment,
the span of immediate memory, and of the span of attention. This limit (or these limits?) of about
seven, plus or minus two, has (or have) since figured prominently in information processing
theories. Miller (1956: 91) warned against assuming “that all three spans are different aspects of
a single underlying process”. But “generality” is a relevant dimension of empirical progress.
Thus it is still tempting to search for one “underlying process” or for one “covering law” for
several regularities corresponding with each other in a certain respect.
Arguments presented in Fenk-Oczlon & Fenk (2001a,b) point to the behavioral relevance
of the magical number 7 in general – independently of the sense modality of the input or even
independently of whether the respective activity is of rather afferent/perceptual or
efferent/motoric nature, and independently of whether one analyzes activities of human beings
or non-human animals. As suggested by the experimental findings by Köhler (1952) with birds and
by Brannon & Terrace (2000) with non-human primates, this limit of about 7 is no specific
characteristic of human information processing. A fascinating finding is reported by Kareev
(2000): Small series of about 7 plus minus 2 data pairs produce stronger correlations between the
respective variables than the population. This would mean that a span of comprehension
comprising about 7 elements or chunks of elements does not reflect a rather arbitrary cognitive
limit, but that there must have been a selective advantage and selective pressure for pushing up
the limit to this region where minimal indications and minimal contingencies can be detected
with a minimum of “computational” work.
All these findings were discussed as indicating some general, extralinguistic or prelinguistic
cognitive preconditions of language, i.e. some sort of “matrix” allowing for as well as
constraining the evolution of our complex language system. Is it possible to see some more
specific communalities, if one concentrates on those limits that seem to occur in different fields
of linguistic research?
Linguistic information is a special type of message processed by our cognitive apparatus. If
the number seven marks some general limits of this apparatus, it should also show in languages,
because language must have developed in adaptation to the general constraints of this apparatus
(Fenk-Oczlon & Fenk 2001a).” (My emphasis)